// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// MediaStreamProvider is used to capture media of the types defined in
// MediaStreamType. There is only one MediaStreamProvider instance per media
// type and a MediaStreamProvider instance can have only one registered
// listener.
// The MediaStreamManager is expected to be called on Browser::IO thread and
// the listener will be called on the same thread.

#ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_PROVIDER_H_
#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_PROVIDER_H_

#include <list>
#include <string>

#include "base/memory/ref_counted.h"
#include "content/common/content_export.h"
#include "content/common/media/media_stream_options.h"

namespace base {
class SingleThreadTaskRunner;
}

namespace content {

enum MediaStreamProviderError {
    kMediaStreamOk = 0,
    kInvalidMediaStreamType,
    kInvalidSession,
    kUnknownSession,
    kDeviceNotAvailable,
    kDeviceAlreadyInUse,
    kUnknownError
};

enum { kInvalidMediaCaptureSessionId = 0xFFFFFFFF };

// Callback class used by MediaStreamProvider.
class CONTENT_EXPORT MediaStreamProviderListener {
public:
    // Called by a MediaStreamProvider when a stream has been opened.
    virtual void Opened(MediaStreamType stream_type, int capture_session_id) = 0;

    // Called by a MediaStreamProvider when a stream has been closed.
    virtual void Closed(MediaStreamType stream_type, int capture_session_id) = 0;

    // Called by a MediaStreamProvider when the device has been aborted due to
    // device error.
    virtual void Aborted(MediaStreamType stream_type, int capture_session_id) = 0;

protected:
    virtual ~MediaStreamProviderListener() { }
};

// Implemented by a manager class providing captured media.
class CONTENT_EXPORT MediaStreamProvider
    : public base::RefCountedThreadSafe<MediaStreamProvider> {
public:
    // Registers a listener and a device message loop.
    virtual void Register(MediaStreamProviderListener* listener,
        const scoped_refptr<base::SingleThreadTaskRunner>&
            device_task_runner)
        = 0;

    // Opens the specified device. The device is not started and it is still
    // possible for other applications to open the device before the device is
    // started. |Opened| is called when the device is opened.
    // kInvalidMediaCaptureSessionId is returned on error.
    virtual int Open(const StreamDeviceInfo& device) = 0;

    // Closes the specified device and calls |Closed| when done.
    virtual void Close(int capture_session_id) = 0;

protected:
    friend class base::RefCountedThreadSafe<MediaStreamProvider>;
    virtual ~MediaStreamProvider() { }
};

} // namespace content

#endif // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_PROVIDER_H_
